I firmly believe that great actors understand human behavior better than do trained psychologists. Yes, that's a sweeping generality, and no, I don't mean every great actor or every trained pscyhologist. Nevertheless, this production of O'Neill's Hughie and Beckett's Krapp's Last Tape at the Goodman Theatre does nothing to shake my faith in that conviction.

Grief is a difficult emotion for an actor to portray without cloying his audience. And the two characters whom Brian Dennehy plays in these two one-act plays are grieving. Each has lost something irretrievable, Erie Smith his illusory sense of importance and Krapp his idealism, sensuality, and eloquence of earlier years. Dennehy's two portrayals of grief were sensitive to degree, nature, and cause. He distilled the common essence -- an appreciation for the loss itself and for its permanence -- while giving us two starkly different manifestations of grief. Smith's loss led him to a calm and resigned disappointment, whereas Krapp's brought about bitterness and anxiety.

Granted the stark difference between the two styles of O'Neill and Beckett, Dennehy himself forged a persuasive concept of each man's personality, at least in relationship to loss. In so doing, his characters expanded into all the dimensions open to them, like a gas fills its container.

Hughie is a two-man play in which a small-time hustler, Erie Smith, explains to the night clerk of his hotel how Lady Fortune has forsaken him since the death of the clerk's predecessor, Hughie. Even though Smith may have found a substitute for Hughie in the night clerk, played somewhat awkwardly by Joe Grifasi, his lost self-importance remains irretrievable. While there are certainly other men (and probably women) whom Smith could play as suckers, Dennehy made it clear that none could fill the void left by Hughie's death. One might argue that there was uniqueness in the power Smith felt as a result of manipulating Hughie, but Dennehy implied more; it was vague but palpable, something a good bit harder to replace. In the uncertainty Dennehy created, there was regard for Hughie as something more than a mark, more than a "sucker", as Smith calls him several times. This Smith seemed to admire Hughie, respect him, and perhaps even envy him for the simplicity of his outlook on life. But Dennehy even left space for the elevation of Hughie to abstraction, to symbolism of everything Smith derided yet embraced.

In Krapp's Last Tape, it is the titular character's 69th birthday and, per habit, he sits alone at a table listening to an audio tape he'd made on his 39th; he then records a new one, commenting on the previous 12 months of his life. There's a white light above the table, but outside the cone is darkness.

In contrast to Smith, Krapp doesn't engage merely in mournful reflection. There's a strong implication that he's failed, or considers himself as having failed, as a writer. At the age of 69, his memories exist only on audio tape, and the only person talking to him -- not with him, mind you -- is he himself of 30 years earlier, long since dead. For him there is no more writing and no more love. The causes of Krapp's memory loss are the stuff of informed speculation, but alcoholism is not unreasonable, especially in view of his predilection for bananas.

The word "spool" amuses Krapp. He has fun saying the word and playing with it. Earlier he nearly slipped on a banana peel that he'd tossed on the floor. And now, in these few seconds of humorous irony, Beckett brings together the simple truth that a banana peel could be in anyone's future, that such an exit from life would be slapstick, and that Krapp's spool is winding down. So, why not chuckle at the word? Dennehy carries this out with a beautiful smoothness that seems to say, "If you can't change it, why worry about it?"

He listens to himself at 39, in a voice both strong and confident, describing his enjoyment at walking out of the light and back into it, musing on how foolish he was in his twenties, recalling the death of his mother, and recounting a revelation at the end of a pier. A bit later the voice is describing a romantic liaison with a woman, a scene that bewitches the older Krapp as he listens closely, and that brings out the deepest sense of loss in this monodrama. He laments his latest literary disappointment, the deterioration of his sex life, and the disappearance of his passion, all of which Dennehy captures in the man's alternating obstinacy and capitulation, his self-disgust and self-satisfaction, and his embarrassment and pride.

To me, Beckett creates an indistinct feeling of solipsism in this play. On top of the character's singularity, the passing between light and dark, and the frequent silence, the audience has no way of knowing whether what it hears on the tape recording actually happened or whether Krapp himself invented it from his writer's imagination. Dennehy used all of this, along with his impressive acting capital, to put a razor-sharp edge on the final moment, a climax of sudden lucidity, when Krapp peers quietly into the darkness and seems to acknowledge the immutability of his past and the inevitability of his death.